The United States entered World War I in 1917 on the side of the Allies, primarily to ensure that German militarism did not threaten American interests. The US provided significant financial and material support to the Allied powers, and its entry into the war helped tip the balance in favor of the Allies. The American Expeditionary Forces, led by General John J. Pershing, played a crucial role in several key battles, most notably the Meuse-Argonne Offensive. The US military's involvement was instrumental in bringing about the eventual Allied victory in November 1918.
